Wide-band emissions from highly stacked quantum dot structure grown using the strain-compensation technique

We developed a new scheme using modulated stacking of self-assembled InAs QDs on InP(3 1 1)B substrates with strain compensation to fabricate QDs in order to expand the potential bandwidths of QD active regions. A highly stacked QD structure was fabricated by the strain-compensation technique with no degradation of structural and optical qualities. The full-width at half-maximum of the photoluminescence of QDs is expanded to 240 nm in the modulated stacking structure. Carrier transfer from the small QD layer to the large QD layer was observed in the stacking structure with a thin spacer layer.